War is a card game that is one of the easiest to learn and is most likely played at least once by everyone in their childhood.
The rules are simple to follow. Start by taking a regular deck of cards and dividing them up evenly among the players. When each player has their cards, they need to shuffle them before starting.
Some easy ways to divide the cards between two people are to have one player take all the red cards and the other player gets the black cards. If there are four players, each player gets all thirteen cards of one suit.
For odd amounts of players, each person gets dealt the same number of cards. The leftover cards can go off the table. They will not be played. If one person sees which cards they are, then everyone gets to see them.
One by one the players deal one card from their hand face up. The player with the highest card takes all of the cards that are laid face up on the table. For example; if a 2 of diamonds, a 2 of clubs, a 3 of spades, and a 4 of hearts were laid down in one hand; the person who had the 4 of hearts would win all of the cards.
In case of a tie, the players with the tying cards deal three cards face down, then another card face up. The person with the highest card face up wins all. If there is another tie, the tie-breaker gets played repeatedly until there is a winner. Should a tiebreaker be needed and one player does not have enough cards in his or her hand to continue, the other player gets all the cards on default.
One way to vary the game play is to give each person their own deck of cards to start off with. Cards need to go back to their original deck when the game is over, otherwise they could be lost.
Another way to spice up the game is to use the jokers in the deck. If a joker is turned face up for play, the person with the joker wins the hand. In other words, a joker is the only card that can trump an ace.
Eventually one person should end up with all of the cards. This may take an hour, or the better part of the day. You could also stage a time limit on when the game should end if you need to.
This is not a game of skill; it is a game of chance and luck. You have no control over which order the cards come up for play.